1. Field of the Invention
This invention relates to underground irrigation systems generally and more particularly to plastic conducting and emitter pipes and couplings therefore which couplings can include structure for flow control adjustment.
2. Description of the Prior Art
Irrigation systems designed for underground application are well known in the art as are flexible pipes and couplings therefore. Such prior art pipes are shown in U.S. Pat. Nos. 2,798,768; 3,426,544; 4,904,112 and 4,948,295 and examples of couplings are shown in U.S. Pat. Nos. 3,454,290; 4,219,222 and 4,480,856. These devices not only do not adequately prevent blockage in the flow openings in the various pipe configuration but are not adaptable to be easily fit into and secured to couplings in the field and the couplings do not include integral means for adjusting the flow of fluid therethrough.